<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      let str = `abcebccbdfbc1bc_bc2bc3bc9bc`;

      console.log(str.match(/\wbc/g));
      console.log(str.match(/[ef_1]bc/g));
      console.log(str.match(/[1-5]bc/g));
      console.log(str.match(/[a-d]bc/g));
      console.log(str.match(/[A-D]bc/g));
      console.log(str.match(/[0-9]bc/g)); //\d
      console.log(str.match(/[a-z0-9A-Z_]bc/g)); // \w
    </script>
  </body>
</html>
